Pictorial cigarette pack warnings: a meta-analysis of experimental studies

To inform international research and policy, we conducted a meta-analysis of the experimental literature on pictorial cigarette pack warnings.We systematically searched 7 computerised databases in April 2013 using several search terms. We also searched reference lists of relevant articles.We included studies that used an experimental protocol to test cigarette pack warnings and reported data on both pictorial and text-only conditions. 37 studies...